Concepts Guide

Configuration Introduction

UM is designed to be highly configurable. Configuration options are generally given default values to support good performance over a wide variety of use cases, but for users who demand the highest levels of performance, many configuration options allow for optimization.

Where practical, UM's design philosophy is to offer new features that can be enabled via configuration only, without requiring changes to the application source code. This can provide higher performance and reliability just by upgrading, without needing to rebuild the application.

Broadly speaking, there are two kinds of components in a UM-based distributed system that need to be configured:

1. Application programs, linked with the UM library,
2. Informatica daemons (service programs that run in the background), which provide services to the applications.

Application programs are written by users and call UM API functions contained within the UM library. The UM library can be configured using a number of different methods described in Configuration Overview.

Informatica daemons include:

- SRS (Stateful Resolver Service) - provides TCP-based topic resolution services to other components. See SRS Configuration File for configuration details.
- lbmrd (Resolver Daemon) - provides unicast UDP-based topic resolution services to other components. See lbmrd Configuration File for configuration details.
- Stored - provides persistence services. See Configuration Reference for Umestored for configuration details.
- DRO - routes messages between Topic Resolution Domains. See DRO Configuration Reference for configuration details.
- ActiveMQ Broker - provides general queuing services and JMS API. See ActiveMQ Xml Configuration for configuration details.

It is important to remember the different kinds of configuration.

- Applications create UM objects (contexts, sources, receivers) using the UM library. Those objects must be configured to control their operation and behavior using "LBM configuration options". An application typically uses an "LBM configuration file" in either XML or flat format. For full details on LBM configuration options, see UM Configuration Guide
- Informatica daemons (e.g. SRS, Store, DRO) are configured using program-specific configuration files in XML format.
- Informatica daemons (e.g. SRS, Store, DRO) also internally create UM objects (contexts, sources, receivers) using the UM library. Those objects must also be configured using one or more LBM configuration files.